Keep in mind that generally it takes twice as much power to drive the alternator than the device the alternator is powering. You are converting mechanical energy into electrical energy and then back to mechanical energy. If the problem is a squealing belt you are going about this is a pretty convoluted way. It will probably take a double pulley belt drive to operate the alternator if you really do need to get rated power out of it. Look at the way the factory AC is laid out and that will point you in the right direction to solve the belt issues.
The aftermarket A/C system I added to the car cheats big time on the whole compressor belt setup by just using the existing PS pump’s belt circuit.
What this did was take ~50% of the PS belt to pulley contact area away, and the Compressor’s belt contact surface is also limited which has caused this to slip in heavy load conditions.
I looked at the factory A/C belt system and to implement it would require several brackets and idler pulleys that are pretty expensive and\or unattainable. If some one has a donor car that can supply me the parts I’d certainly be interested and willing to pay $!
From what I read on the internet (and it must be true! 
) the PS pump uses ~8HP, while the added load on the alternator is ~1HP. Now going from a 60 amp alternator to a 95amp alternator could indeed load the engine more I agree with that probability.
Looking at all the sites that have alternator upgrades they never indicate the belts need to be resized or doubled up.
And IMHO; If alternators take twice the mechanical energy then the mechanical equivalent to perform the same task, why have so many systems in cars become electrical ? Radiator fans, PS pumps, even water pumps (in some cases) have been converted over to electrical. Not trying to be combative, it’s just my thoughts.
Thx,
Jay
One horsepower is roughly 750 watts. Power, measured in watts, is equal to current times voltage so that tells us that at 15 volts we need 50 amps of current to make 1 HP. So an alternator that can put out 100 amps of current at 15 volts can produce 1500 watts of power, roughly 2 horsepower. However we have to convert the mechanical energy of the engine (the rotation of the crankshaft) into electrical energy in the alternator. Since we know that there is no such thing as perfect energy conversion, it takes the engine more than 2 horsepower to turn the alternator. Typically the alternator itself is about 60% efficient meaning that if you put one horsepower of energy into it (750 watts) you will get 450 watts out of it. All of this is physics so pretty much not a matter of opinion.
So why so many electrical things on new cars? Fuel mileage is number 1. Start / Stop technology means things have to keep working when the engine isn’t running. Power steering, cooling fans for radiator and AC condensor need to keep going. Even where start / stop is not used engines are not efficient at idle and idle mixtures have run richer to make a little more torque, or in some cases idle speeds have to increase to accommodate the accessories. It is also possible to computer control voltage regulation to minimize the rate of charge when the engine is at low RPMs, and to do most charging at higher RPMs. When you no longer rely on the engine for power you can begin to modulate things like steering effort and braking effort electronically. Almost everything in a modern car is being operated by a computer that is communicating on a bus. It is easier to build in functions electronically than mechanically.
I’m an electrical engineer who before working on ABS, RSC, TC, YSC, regenerative braking ,etc., was working on Electric Power Steering. What you’re talking about is what we called Electrically Powered Hydraulic Steering (EPHS).
A steering system experiences it’s maximum forces when you are turning while braking. Think of that case where you see your turn a little late, or that parking space that you almost didn’t see. And when this happens your engine is at idle.
An engine driven PS pump needs to be sized to provide enough fluid flow and pressure to move that cylinder when the engine is at idle
I think XR7G428’s point was that every watt or ftlbrpm of power used in your car comes off the crankshaft. There is no other source. The mechanical systems have their load more or less constantly. The PS pump is a good example of a fairly constant load. The benefit of an EPHS system is that the motor operates at a reduced output (speed) under low steering load situations. That means there needs to be sensors to determine when the motor output can be reduced and when it needs to be increased to maintain the assist level and controllability. When the pump output needs to rise to keep up with the steering demand, the electrical load will also increase. Some of this will be immediately supplied by the battery, but the voltage regulator will quickly see the falling voltage and increase the field current to the alternator, which will increase the torque it is applying against the crankshaft rotation, the only power source.
Without the sensors and controls, your least unsafe option is to run the pump full tilt, which is a loser on the efficiency front as XR7G428 alludes to above.
What you are both saying makes complete sense, I appreciate you clarifying your points to me.
Sounds like I wasn’t that far off from the 1 HP added load, since the electrical PS pump draws around 40 amps.
So my best solution is to find a donor car that had A/C and salvage all the A/C brackets, idlers, crank pulleys etc. to implement the factory belt system?
With that option possibly not available or cost prohibitive, the next best possible course of action would be?
I think keeping the two belt system I currently have and having a dedicated belt for only the A/C and an electric/hydraulic PS system, although not optimal, is a viable solution and possibly much less expensive.
I also have a 69 M code vert. As you may have surmised I live in the Detroit area, so the car is stashed away for the winter. Otherwise I would post some pictures of the belting. I think you need to be able to move the compressor forward, find the accessory pulley that bolts to the front of the vibration damper, and then an idler to tension the belt. That would set you up with a belt that only runs the compressor and restores enough wrap to the PS pump pulley.
I would start by checking with the add-on A/C supplier. This can’t be the first time this has come up. Add-on A/C has been around longer than our cars have been.
One other thing to keep in mind about our vintage alternators is the rated output is when the alternator is cold. As the windings heat up, their resistance goes up and the maximum output goes down. Something to keep in mind for adding electric fans or water pumps.
PonyCarman,
I was thinking the same thing. They may have a solution available, I’ll contact them on Monday. The Compressor bracket does look like the compressor could be mounted farther out so a 3rd belt could catch it. One of the issues with the (alternator side) idler is it requires a special spacer/bracket, that is not available at WWCC so I’d have to source it somewhere else (even if WWCC had one in stock they wanted way too much for it). I guess I could attempt to fabricate it. Not sure if the idler on the drivers side requires any special bracketing to mount correctly.
Thx,
Jay
I don’t recall an idler on the passenger side. The alternator swings to tension the belt. My car is an automatic and even though it is a California car it doesn’t have the smog pump. As a manual does yours have the smog pump? Is that on the passenger side?
I reread the topic and you don’t mention what you have as a voltage regulator right now. The reason I ask is because if you are running the mechanical style regulator, you are getting charge power in steps or pulses rather than smooth adjustments. If you are noticing oddities with your fuel injection system, irregular voltage could cause that.
I don’t know the specifics of your Holley EFI system, but typically the controllers that energize coils use the battery voltage they get on their largest power input terminal without regulation. With modern charging systems this voltage is smooth enough to give consistent results. When the voltage becomes irregular, the results become irregular. Garbage in, garbage out.
I was reminded of this when my diesel pickup started running like crap. I was expecting the dreaded LB7 fuel injector replacement festivities. A few hundred miles later I noticed voltage fluctuation. In that case it was the alternator failing and the regulator was trying to compensate for the irregular output which meant the voltage would swing from about 9 to 17 volts. Fixed that, the injector coils were now getting consistent current, and the diesel ran smoothly again.
PCM,
My car has the original mechanical regulator and alternator ( I believe) and there is no smog pump.
From what I see in the assembly manuals I have, there are 2 idlers in the A/C belt system one on the passenger side and one on the drivers side.
I have a 2 pulley system currently and the aftermarket A/C shares the PS pulley. This is what I’m trying to address, I want a separate pulley on the A/C compressor and the PS pump, or replace the PS pump with an electric pump.
There is no idler in the alternator belt setup.
I’d also need to upgrade my Crank pulley to support a 3rd belt (A/C belt system).
Thx,
Jay
Check out an earlier thread “How screwed am I?” https://cccforum.discoursehosting.net/t/how-screwed-am-i/12790/1
It looks like your problem. You might PM the OP to see what worked for him.
The picture of the front of the engine shows what you mean by the passenger side idler. It is so close to the center of the engine I never realized it was actually on the passenger side. I’m not sure my car has the one on the driver side. That was to control belt slap. Not all Fords of the era had that idler.
BTW - Since you’re running the mechanical regulator with EFI, you’ll probably notice more consistent engine performance by upgrading to an electronic regulator.
After a lot of research, the most obvious solution came to me, get a 3-groove water pump pulley along with a 3-grove crank pulley and now you can run the A/C on the 3rd groove. Just need to move the A/C compressor out a bit to align it with the 3rd groove (the mechanism that I have is adjustable).
Won’t need any idlers or additional brackets, simple and cheap(er)! CVF Racing cvfracing.com has a 3-grove water pump pulley that works with a 3 bolt crack pulley/driver side lower radiator hose 351W configuration. Apparently the radiator hose configuration makes the pulley position change.
Why Ford didn’t do this originally eludes me, but I’m sure they had their reasons.
Jay
Sounds like a good solution. How do you tension the A/C belt with that setup?
The after market A/C bracket setup has a tensioning feature on the compressor.
I’ll have to figure out the new belt size, but I I had to do that with the current setup as neither configuration is stock.
Jay
You just solved my low voltage issue at idle for my Sniper EFI. I ordered their adapter harness and 3g alternator. Thanks!
You just solved my low voltage issue at idle for my Sniper EFI. I ordered their adapter harness and 3g alternator. Thanks!
This seems to be a good article for a 3G upgrade.
Glad I could be of some help. Good luck with the upgrade.
I’m going to be using their (fake) voltage regulator as it allows you to keep the exiting wiring (with an additional high current wire off the Alternator), but I’m using a different 3G alternator, I wanted more power than 95 amps.
I found the Holley Sniper EFI upgrade exposes all the things that are wrong with your engine that a carburetor didn’t care about, so it always more work than you think. Exhaust leaks being the biggest issue for me.
Yep, I got their fake external regulator box with the 3G harness adapter. Will install it all when I get my converted amp meter to volt meter from Rocket man. (I just ordered it and am shipping him my amp meter on Monday) apparently the 3G upgrade is too many amps for our old amp meters.
That is a good article, thanks!
So this thread has kinda of morphed into an Crank Pulley and belt discussion.
My Thread https://cccforum.discoursehosting.net/t/advice-with-replacing-the-crank-and-water-pump-pulleys/13681/1 discusses the solution that I can up with to address that.